Companies begin defense in Gulf oil spill trial

The owner of the drilling rig that exploded at the outset of the 2010 Gulf of Mexico oil spill catastrophe started its defense Monday at a trial designed to determine the disaster's causes and assign fault to the companies involved.

The owner of the drilling rig that exploded at the outset of the 2010 Gulf of Mexico oil spill catastrophe started its defense Monday at a trial designed to determine the disaster's causes and assign fault to the companies involved.

Transocean Ltd. called its first witness, well control expert Calvin Barnhill, on the 13th day of the trial. Transocean president and CEO Steven Newman was scheduled to testify Tuesday.

U.S. District Judge Carl Barbier already has heard testimony by more than a dozen witnesses called by the Justice Department and attorneys for Gulf Coast businesses and residents who claim the spill cost them money. The plaintiffs' lawyers still expect to call another witness to the stand this week, an employee of cement contractor Halliburton.

Tranoscean's witnesses could take up the rest of the trial's fourth week. Halliburton and Macondo well owner BP PLC plan to call their own witnesses after Transocean finishes.

The judge is hearing the case without a jury and — barring a settlement — could decide how much more money BP and its contractors owe for their roles in the catastrophe. BP could be on the hook for nearly $18 billion in penalties under the Clean Water Act if the judge finds that it acted with "gross negligence."

The explosion on the Deepwater Horizon rig in the Gulf of Mexico on April 20, 2010, killed 11 workers and led to the nation's worst offshore oil spill.

After a plaintiffs' expert finished testifying Monday, BP attorney Andy Langan asked Barbier to rule that the plaintiffs haven't proved the London-based oil giant acted with gross negligence or willful misconduct. Barbier said he wasn't ready to rule on that request yet.

M-I LLC, BP's drilling fluids contractor on the Macondo well, asked the judge on Monday to dismiss all of the plaintiffs' claims against the company. M-I attorneys argued the plaintiffs haven't presented any evidence that M-I made any decision that led to the blowout. Barbier didn't immediately rule on M-I's request, either.

The plaintiffs' attorneys have accused BP and its contractors of cutting corners and sacrificing safety in a rush to save time and money on a project that was behind schedule and millions of dollars over budget. BP leased the rig from Swiss-based Transocean.

Barnhill, a petroleum engineer, testified Monday that Tranocean's drilling crew was properly trained in accordance with industry standards. He described the Deepwater Horizon as a "state-of-the-art" rig that drilled at depths few others ever had.

Barnhill also testified that BP ultimately was responsible for determining whether the results of a crucial safety test were properly interpreted on the day of the blowout.

Page 2 of 2 - Two BP rig supervisors, Robert Kaluza and Donald Vidrine, are charged with manslaughter in the 11 rig workers' deaths and await a separate trial. An indictment last year accuses Kaluza and Vidrine of botching the safety test and disregarding abnormally high pressure readings that should have been glaring signs of trouble just before the explosion.